J/A+A/665/A135ivo://CDS.VizieR/J/A+A/665/A135doi:10.26093/cds/vizier.36650135CDSMontelius M.Forsberg R.Ryde N.Joensson H.Afsar M.Johansen A.,Kaplan K.F.Kim H.Mace G.Sneden C.Thorsbro B.2022-09-28T05:52:06Z2022-09-21T07:05:56ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frk-starsgiant-starschemical-abundancesinfrared-astronomyspectroscopymilky-way-galaxyMeasuring the abundances of neutron-capture elements in Galactic disk stars is an important part of understanding key stellar and galactic processes. In the optical wavelength regime a number of different neutron-capture elements have been measured; however, only the s-process-dominated element cerium has been accurately measured for a large sample of disk stars from the infrared H band. The more r-process dominated element ytterbium has only been measured in a small subset of stars so far. In this study we aim to measure the ytterbium (Yb) abundance of local disk giants using the Yb II line at {lambda}_air_=16498{AA}. We also compare the resulting abundance trend with cerium and europium abundances for the same stars to analyse the s- and r-process contributions. We analyse 30K giants with high-resolution H band spectra using spectral synthesis. The very same stars have already been analysed using high-resolution optical spectra via the same method, but it was not possible to determine the abundance of Yb from those spectra due to blending issues for stars with [Fe/H]>-1. In the present analysis, we utilise the stellar parameters determined from the optical analysis. We determined the Yb abundances with an estimated uncertainty for [Yb/Fe] of 0.1dex. By comparison, we found that the [Yb/Fe] trend closely follows the [Eu/Fe] trend and has clear s-process enrichment in identified s-rich stars. This comparison confirms both that the validity of the Yb abundances is ensured and that the theoretical prediction that the s-/r-process contribution to the origin of Yb of roughly 40/60 is supported. These results show that, with a careful and detailed analysis of infrared spectra, reliable Yb abundances can be derived for a wider sample of cooler giants in the range -1.1<[Fe/H]<0.3. This is promising for further studies of the production of Yb and for the r-process channel, key for galactochemical evolution, in the infrared.2022A&A...665A.135Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/665/A135CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/631/A113 : Abund. of disk+bulge giants: Zr, La, Ce, Eu (Forsberg+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/665/A135https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/665/A135http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/665/A135https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/665/A135https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/665/A135http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/665/A135GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/665/A135/table1 (Observational data for sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/665/A135/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/665/A135/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/665/A135/table1?GETtext/xml+votable180.050000true213.915300319.18240920.0055555555555555566/4444 4574 5982 6219 8767 9665 9753 10584 11929 13282 14585 14591 14730 14735 14746 14753 14757 14825 14827 14936 14948 14954 15148 15153-15154 15176 16035 26078 265521.1166583743361574e-19 1.2918781580533825e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/665/A135?format=asciiInfrareddefaultJ/A+A/665/A135/table1Observational data for samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarName (HD, HIP, KIC, 2M)meta.id;meta.maincharn_Star[a] Note on Star (G1)meta.notechar2MASS2MASS name (JHHMMSSss+DDMMSSs)meta.idcharHmag2MASS H magnitudemagphot.mag;em.IR.HfloatKmag2MASS K magnitudemagphot.mag;em.IR.KfloatDateObservation datetime.epoch;obsnullableTelUsed telescope (1)instr.setupcharExpTimeExposure timestime.duration;obs.exposureintSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/A+A/665/A135/table3Stellar parameters and abundances for samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarName (HD, HIP, KIC, 2M)meta.id;meta.maincharn_Star[a] Note on Star (G1)meta.notecharTeffEffective temperatureKphys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H]Relative iron abundancephys.abund.FefloatvmicMicroturbulence velocitykm/sphys.veloc.microTurbfloatDist? Distance (1)pcpos.distanceintnullablePopDesignated stellar population (2)meta.code.classcharS/NSignal-to-noise ratio (3)stat.snrint[Yb/Fe]Relative Ytterbium abundancephys.abundfloat[Eu/Fe]? Relative Europium abundance (4)phys.abundfloatnullable[Ce/Fe]Relative Cerium abundancephys.abundfloat